hey man, welcome to the forum!

yes, you are correct, you should use the deca and test together. i will assume you want to put on size... in which case the stanozol is really pointless, you can put that back on the shelf and save it for the future.

personally, i would source some more of both deca and test asap.. you dont want to run out and then have a gap while you wait for your *doctor* to prescribe you more

as for injections volume/frequency, do 1/2cc deca + 1cc test, every other day, so mon wed fri sun tues etc. when you are near the end of the cycle, drop the deca, and do 1cc test EOD for 3-4 weeks, before starting your PCT

which brings up another point, have you planned your PCT yet?